Accessing ACPI MSDM From UEFI Shell

This post is an update on my February 2015 post on how to retrieve your Microsoft Windows 8 or later product key from your firmware via the ACPI MSDM (Microsoft Data Management) table and the UEFI Shell. You should read that post if you are unfamiliar with the ACPI MSDM table. Of note is the fact that the ACPI specification is now managed by the UEFI Forum.

The original version of this utility was named ListMSDM.efi and used Nigel Croxon’s excellent GNI-EFI library. This version is named ShowMSDM.efi and is based on the UDK2017 snapshot of the TianoCore EDK2 (EFI Development Kit, Version 2.)

1 comment to Accessing ACPI MSDM From UEFI Shell

Well, now understand why after buying a refurbished Thinkpad x260 laptop, noticed reinstalled windows 10 home version was setup with BIOS in legacy boot mode (because I was setting a Linux double boot, otherwise I would not have noticed not being in UEFI mode)… so decided to reinstall from USB media…

With a surprise in the end:
Reinstalled win10 (with BIOS now in UEFI mode) was no more a home version, but a pro one!

As Thinkpads are sold with a OEM pro licence, I suppose this license was still present in UEFI but no more used in legacy mode (probable reason why reseller switched to legacy mode: Being able to install it’s home refurbished PC licence… and charge you 50 bucks more if you want pro version!).

I didn’t really needed a pro version, only interesting feature is being able to tune some automatic upgrade delays, thus not getting in bugs triggered by the new “rolling-release” nature of win10: They’ll hit others, beings removed & reworked, before me.